Kisspeptin-10
KP-10, metastin (45–54), kisspeptin 112–121, KISS1 peptide; the full-length form is kisspeptin-54 (metastin)
1What it is
Kisspeptin is a hormone the body already makes. The KISS1 gene — named by researchers in Hershey, Pennsylvania (home of Hershey's Kisses) who first found it as a tumour-suppressor in 1996 — produces a 54-amino-acid peptide that is cut into shorter active forms, of which kisspeptin-10 is the smallest. In 2003 two groups showed that people born without a working kisspeptin receptor do not go through puberty, which revealed kisspeptin as the master switch of the reproductive hormone axis (Seminara 2003; de Roux 2003). It is also expressed in the placenta (blood levels rise thousands-fold in pregnancy) and in brain regions involved in emotion and sexual processing.
As a research compound kisspeptin-10 is the synthetic copy of that natural fragment. Human work has come mainly from Imperial College London (Dhillo, Jayasena, Comninos) and from fertility groups testing kisspeptin-54 as a safer trigger for egg maturation in IVF. The community interest is in using it to raise testosterone or restore natural LH output without suppressing the axis, and for libido.
2How it's thought to work
3What the research shows
Stimulates LH and testosterone in healthy men
Stimulates LH in women
Hypogonadotropic hypogonadism
IVF egg maturation trigger
Sexual and emotional brain processing, libido
Diagnostic test for puberty disorders
Testosterone replacement alternative, "PCT", body composition
4Reported side effects and interactions
Literature-reported
generally well tolerated in hundreds of research-study exposures; no serious adverse events reported in healthy volunteers. Injection-site reactions, occasional flushing and mild nausea. Tachyphylaxis (fading response) with continuous or very frequent dosing. Transient rises in LH, FSH, testosterone or oestradiol are the intended effect but mean the hormone profile shifts for hours.Community-reported
increased libido, mood lift, improved erections, flushing, headache, slight nausea, injection-site itching; some report no noticeable effect at low doses.Theoretical. in people with hormone-sensitive conditions (prostate cancer, oestrogen-dependent cancers, endometriosis) stimulating the axis is undesirable. Desensitisation with overuse could in theory lower rather than raise output. Very high kisspeptin levels occur naturally in pregnancy, so pregnancy itself is not a toxicity concern, but no one has studied exogenous dosing in pregnancy.
Interactions. GnRH /antagonists and hormonal contraceptives alter or block the response; exogenous testosterone or anabolic steroids suppress the axis, so kisspeptin's effect would be blunted. Opioids and high prolactin suppress kisspeptin neurons.
Markers researchers commonly monitor
| Marker | Why it's watched |
|---|---|
| LH and FSH | the direct read-out of the effect, best measured 30–60 minutes after a dose and at baseline. |
| Total and free testosterone (men) or oestradiol and progesterone (women) | the downstream outcome; timing relative to dosing matters. |
| Sex hormone-binding globulin | helps interpret total testosterone. |
| Prolactin | high prolactin blunts the response; a baseline helps explain a non-response. |
| Haematocrit and PSA (men) | standard when testosterone is being raised by any route. |
| Menstrual cycle tracking and ovulation markers (women) | kisspeptin can advance or trigger ovulation. |
Free for everyone. Safety information is never behind a paywall.
5Reconstitution and handling
Usually supplied as 5 mg or 10 mg vials. with , swirl, keep cold. Short peptides with free ends degrade faster than cyclic ones; community practice is to make smaller batches.
Open in calculator, pre-loaded →6Commonly studied alongside
Gonadorelin and HCG (the next two steps down the same axis — often compared, sometimes alternated in community protocols); clomiphene and enclomiphene (different mechanism, same aim); PT-141 (sexual-function research line); neurokinin B and NK3 receptor antagonists (fezolinetant — the hot-flush drug — works on the KNDy neurons).
Informational cross-links. Not stack recommendations.
7Regulatory status by region
| Region | Status (checked —) |
|---|---|
| United States | Not FDA-approved; placed in Category 2 of FDA's bulk drug substances list for compounding (2023), restricting compounding |
| European Union | Not authorised; investigational |
| United Kingdom | Not licensed; used in research under clinical trial authorisation |
| Australia | Not approved † |
| South Africa | Not registered † |
| Sport (WADA) | Not named; as a non-approved substance it falls under S0, and anything that raises testosterone may be relevant to S1/S2 interpretation † |
8Open questions
- Does intermittent kisspeptin raise testosterone durably in men without desensitising the system? Only days-to-weeks data exist.
- The right dosing rhythm to avoid tachyphylaxis.
- Whether the brain effects on sexual processing translate into clinical benefit for HSDD.
- Kisspeptin-54 vs kisspeptin-10: the human data are split between the two forms.
9References
- 1Seminara SB et al. (2003). The GPR54 gene as a regulator of puberty. N Engl J Med. PubMed · DOI
- 2de Roux N et al. (2003). Hypogonadotropic hypogonadism due to loss of function of the KiSS1-derived peptide receptor GPR54. Proc Natl Acad Sci USA. DOI
- 3Dhillo WS et al. (2005). Kisspeptin-54 stimulates the hypothalamic-pituitary gonadal axis in human males. J Clin Endocrinol Metab. PubMed · DOI
- 4Dhillo WS et al. (2007). Kisspeptin-54 stimulates gonadotropin release most potently during the preovulatory phase of the menstrual cycle in women. J Clin Endocrinol Metab. PubMed · DOI
- 5Jayasena CN et al. (2009). Subcutaneous injection of kisspeptin-54 acutely stimulates gonadotropin secretion in women with hypothalamic amenorrhea, but chronic administration causes tachyphylaxis. J Clin Endocrinol Metab. PubMed · DOI
- 6George JT et al. (2011). Kisspeptin-10 is a potent stimulator of LH and increases pulse frequency in men. J Clin Endocrinol Metab. PubMed · DOI
- 7George JT et al. (2013). Exploring the pathophysiology of hypogonadism in men with type 2 diabetes: kisspeptin-10 stimulates serum testosterone and LH secretion in men with type 2 diabetes and mild biochemical hypogonadism. Diabetes Obes Metab. PubMed · DOI
- 8Jayasena CN et al. (2014). Kisspeptin-54 triggers egg maturation in women undergoing in vitro fertilization. J Clin Invest. PubMed · DOI
- 9Abbara A et al. (2015). Efficacy of kisspeptin-54 to trigger oocyte maturation in women at high risk of ovarian hyperstimulation syndrome (OHSS) during in vitro fertilization (IVF) therapy. J Clin Endocrinol Metab. PubMed · DOI
- 10Comninos AN et al. (2017). Kisspeptin modulates sexual and emotional brain processing in humans. J Clin Invest. PubMed · DOI
- 11Thurston L et al. (2022). Effects of kisspeptin administration in women with hypoactive sexual desire disorder: a randomized clinical trial. JAMA Netw Open. PubMed · DOI
- 12Mills EG et al. (2023). Effects of kisspeptin on sexual brain processing and penile tumescence in men with hypoactive sexual desire disorder: a randomized clinical trial. JAMA Netw Open. PubMed · DOI
- 13FDA (2023). Bulk drug substances for compounding — kisspeptin-10 category 2 listing. PubMed
References are being resolved to PubMed/DOI identifiers; links search PubMed for the citation until then.
† Being confirmed by our reviewers against current sources.
10Community
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Self-reported side effects Phase 2
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